Monster 6502

dwight dkelvey at
Sat May 28 14:01:55 CDT 2016

Eric had it at the Maker Faire. He'd covered it with a antistatic
plexiglass but it still had some static sensitivity.
He was exercising it with ( I think ) a R Pi. He'd been depending
on the gate capacitance only. I told him that to get it a little more
reliable, he would need to increase the capacitance a little for the floating
nets. It will cost a little on power but there isn't that high a toggle
on all of the nets that are dynamic.
10 to 20 pf should make it more stable.
He needed a separate body attachment for the transmission gates.
Al he could find were multi transistor packs.
Most all of the important buss and status locations have LEDs on them.
The layout is close as practical to the original silicon.

From: cctalk <cctalk-bounces at> on behalf of Eric Smith <spacewar at>
Sent: Saturday, May 28, 2016 10:31:39 AM
To: General Discussion: On-Topic and Off-Topic Posts
Subject: Re: Monster 6502

On Sat, May 28, 2016 at 5:31 AM, Corey Cohen <applecorey at> wrote:
> I can't wait to buy one!!!  I have a spare Replica-1 just waiting to hook up to a Monster 6502.

It doesn't run at full speed. It presently runs in the tens to low
hundreds of kHz.  If a Replica-1 can be run slower than normal, that
might work.  Other common 6502-based micros, such as the Apple II or
Atari 400/800 will not work at low speed due to inherent timing
requirements related to video generation and DRAM refresh.

> Just need to wire up a single step switch and this thing will be awesome!!!

If you wire single-stepping using the RDY line, that should work,
though it will only single-step read cycles, not write cycles.

You can't single-step the actual clock because it is dynamic logic.

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